The length of a rectangular piece of steel in a bridge is 4 meters less than triple the width. The perimeter is 64 meters. Find the length and width

Mathematics · High School · Tue Nov 03 2020

Answered on

So we know that a rectangular has 2 widths (W) and 2 lengths (L) and its perimeter is P=2L+2W

From the exercise we know this : L=3W-4

If we put that on our top perimeter equation we have this: 

P= 2(3W-4)+2W

P=6W-8+2W

P=8W-8

64=8W-8

8W=72

W=9 meters that means that width is 9 meters

If we substitute W=9 on this equation L=3W-4 we will have L=3*9 - 4

L=27-4

L=23 meters so that means length is 23 meters